1. Field of Invention
The present invention relates to a semiconductor manufacturing technology, and more particularly to an MIM capacitor useful in analog and mixed signal processing and a method of manufacturing the MIM capacitor.
2. Description of Related Art
Since thin-film capacitors, such as PIP (Poly-Insulator-Poly) capacitors, MIM (Metal-Insulator-Metal) capacitors and the like, are generally independent from bias (different from MOS capacitors or junction capacitors), the thin-film capacitors have been mainly used for analog products benefiting from precision of capacitors.
Further, there is a disadvantage in that it is difficult to manufacture MIM capacitors which have a relatively large capacitance per unit area than PIP capacitors, while there is an advantage in that the MIM capacitors have superior VCC or TCC of capacitance (depending on a voltage or temperature) relative to the PIP capacitors. For this reason, the MIM capacitors are advantageous for manufacturing precise analog products.
FIG. 1 is a sectional view of an MIM capacitor according to a related art.
In a method of manufacturing the MIM capacitor according to the related art, a dielectric layer 3 and an upper metal layer 4 are first deposited on lower metal layers 2a and 2b of a substrate 1 formed with a predetermined structure.
Then, the dielectric layer 3 and the upper metal layer 4 in an area to be formed with a capacitor are etched by using a mask (not shown), thereby forming an MIM capacitor 5.
Subsequently, an interlayer dielectric layer 6 is formed on the entire surface of the substrate 1, and following processes are then performed.
According to the related art, the structure of a completed MIM capacitor is a substantially two-dimensional structure, in which an insulating material is interposed between upper and lower metal layers.
However, since there are limitations for increasing capacitance in such a two-dimensional MIM structure, any significant increase in capacitance should solve such two-dimensional limitations.